feature #603: add static method [std::string description()] to manifest

Author: facontidavide

include/behaviortree_cpp/basic_types.h

@@ -413,6 +413,19 @@ struct has_static_method_providedPorts<
 {
 };
 
+template <typename T, typename = void>
+struct has_static_method_description : std::false_type
+{
+};
+
+template <typename T>
+struct has_static_method_description<
+    T, typename std::enable_if<
+           std::is_same<decltype(T::description()), std::string>::value>::type>
+  : std::true_type
+{
+};
+
 template <typename T> [[nodiscard]]
 inline PortsList getProvidedPorts(enable_if<has_static_method_providedPorts<T>> = nullptr)
 {

include/behaviortree_cpp/bt_factory.h

@@ -44,7 +44,13 @@ template <typename T>
 inline TreeNodeManifest CreateManifest(const std::string& ID,
                                        PortsList portlist = getProvidedPorts<T>())
 {
-  return {getType<T>(), ID, portlist, {}};
+  if constexpr( has_static_method_description<T>::value)
+  {
+    return {getType<T>(), ID, portlist, T::description()};
+  }
+  else {
+    return {getType<T>(), ID, portlist, {}};
+  }
 }
 
 #ifdef BT_PLUGIN_EXPORT

src/xml_parsing.cpp

@@ -909,7 +909,9 @@ void addNodeModelToXML(const TreeNodeManifest& model,
 
   if (!model.description.empty())
   {
-    element->SetAttribute("description", model.registration_ID.c_str());
+    auto description_element = doc.NewElement("description");
+    description_element->SetText(model.description.c_str());
+    element->InsertEndChild(description_element);
   }
 
   model_root->InsertEndChild(element);

tests/gtest_factory.cpp

@@ -1,7 +1,5 @@
 #include <gtest/gtest.h>
 #include <filesystem>
-#include "action_test_node.h"
-#include "condition_test_node.h"
 #include "behaviortree_cpp/xml_parsing.h"
 #include "../sample_nodes/crossdoor_nodes.h"
 #include "../sample_nodes/dummy_nodes.h"
@@ -372,3 +370,36 @@ TEST(BehaviorTreeReload, ReloadSameTree)
     ASSERT_EQ(NodeStatus::FAILURE, tree.tickWhileRunning());
   }
 }
+
+class DescriptiveAction : public SyncActionNode
+{
+public:
+  DescriptiveAction(const std::string& name, const NodeConfig& config):
+    SyncActionNode(name, config) {}
+
+  BT::NodeStatus tick() override {
+    return NodeStatus::SUCCESS;
+  }
+
+  static PortsList providedPorts() {
+    return {};
+  }
+
+  static std::string description() {
+    return "THE DESCRIPTION";
+  }
+};
+
+TEST(BehaviorTreeFactory, DescriptionMethod)
+{
+
+  BehaviorTreeFactory factory;
+  factory.registerNodeType<DescriptiveAction>("DescriptiveAction");
+  const auto& manifest = factory.manifests().at("DescriptiveAction");
+  ASSERT_EQ(manifest.description, "THE DESCRIPTION");
+
+  auto xml = writeTreeNodesModelXML(factory, false);
+  std::cout << xml << std::endl;
+
+  ASSERT_NE(xml.find( "<description>THE DESCRIPTION</description>"), std::string::npos);
+}